A comprehensive molecular study on Coffin-Siris and Nicolaides-Baraitser syndromes identifies a broad molecular and clinical spectrum converging on altered chromatin remodeling

Hum Mol Genet. 2013 Dec 20;22(25):5121-35. doi: 10.1093/hmg/ddt366. Epub 2013 Aug 1.

Abstract

Chromatin remodeling complexes are known to modify chemical marks on histones or to induce conformational changes in the chromatin in order to regulate transcription. De novo dominant mutations in different members of the SWI/SNF chromatin remodeling complex have recently been described in individuals with Coffin-Siris (CSS) and Nicolaides-Baraitser (NCBRS) syndromes. Using a combination of whole-exome sequencing, NGS-based sequencing of 23 SWI/SNF complex genes, and molecular karyotyping in 46 previously undescribed individuals with CSS and NCBRS, we identified a de novo 1-bp deletion (c.677delG, p.Gly226Glufs*53) and a de novo missense mutation (c.914G>T, p.Cys305Phe) in PHF6 in two individuals diagnosed with CSS. PHF6 interacts with the nucleosome remodeling and deacetylation (NuRD) complex implicating dysfunction of a second chromatin remodeling complex in the pathogenesis of CSS-like phenotypes. Altogether, we identified mutations in 60% of the studied individuals (28/46), located in the genes ARID1A, ARID1B, SMARCB1, SMARCE1, SMARCA2, and PHF6. We show that mutations in ARID1B are the main cause of CSS, accounting for 76% of identified mutations. ARID1B and SMARCB1 mutations were also found in individuals with the initial diagnosis of NCBRS. These individuals apparently belong to a small subset who display an intermediate CSS/NCBRS phenotype. Our proposed genotype-phenotype correlations are important for molecular screening strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abnormalities, Multiple / genetics*
  • Abnormalities, Multiple / pathology
  • Adolescent
  • Adult
  • Carrier Proteins / genetics
  • Child
  • Child, Preschool
  • Chromatin Assembly and Disassembly / genetics*
  • Chromosomal Proteins, Non-Histone / genetics
  • DNA-Binding Proteins / genetics
  • Exome / genetics
  • Face / abnormalities*
  • Face / pathology
  • Facies
  • Female
  • Foot Deformities, Congenital / genetics*
  • Foot Deformities, Congenital / pathology
  • Hand Deformities, Congenital / genetics*
  • Hand Deformities, Congenital / pathology
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Hypotrichosis / genetics*
  • Hypotrichosis / pathology
  • Infant
  • Infant, Newborn
  • Intellectual Disability / genetics*
  • Intellectual Disability / pathology
  • Karyotyping
  • Male
  • Micrognathism / genetics*
  • Micrognathism / pathology
  • Mutation, Missense
  • Neck / abnormalities*
  • Neck / pathology
  • Repressor Proteins
  • SMARCB1 Protein
  • Sequence Deletion / genetics*
  • Transcription Factors / genetics

Substances

  • ARID1B protein, human
  • Carrier Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • PHF6 protein, human
  • Repressor Proteins
  • SMARCB1 Protein
  • SMARCB1 protein, human
  • Transcription Factors

Supplementary concepts

  • Coffin-Siris syndrome
  • Nicolaides Baraitser syndrome